The present invention relates generally to the field of network environments and more particularly to network security.
A whitelist is a list of entities approved for authorized access or privileged membership to enter a specific area in the computing world. These entities could include electronic groups or organizations, privileged websites or even email addresses. Whitelist may also refer to an actionable promotion or recognition of an organization, group, or individual. This term may also be known as an approved list.
Internet service providers employ whitelists to protect their customers. There are various types of whitelists, including commercial, noncommercial, local area network (LAN), program, and application whitelists. Rather than blacklisting harmful websites, whitelisting is considered to be a proactive measure. Whitelisting is used to allow access to pertinent and safe websites, which may be considered an alternative to the use of anti-malware software.
Regarding emails, a whitelist includes email addresses that are considered acceptable and are therefore not filtered out. Likewise, application whitelists are considered a protective measure to allow only safe applications that do not compromise computer functions or security.
Organizational whitelists are used to make sure that institutions, such as public schools, protect their students against harmful websites. These organizations may allow, or whitelist, only those sites that promote organizational goals, such as those that assist students with classroom assignments.
Commercial whitelists are used to ensure that advertisers are successfully delivering content to their preferred customers. Noncommercial whitelists may also be generated by nonprofit organizations. Blacklist is the opposite of whitelist and refers to a list of entities that are denied, ostracized, or unrecognized for access to the computing world.
A blacklist, or block list, is a basic access control mechanism that allows through all elements (email addresses, users, passwords, URLs, IP addresses, domain names, file hashes, etc.), except those explicitly mentioned. Those items on the list are denied access. The opposite is a whitelist, which means only items on the list are let through whatever gate is being used. A greylist contains items that are temporarily blocked (or temporarily allowed) until an additional step is performed.
Blacklists can be applied at various points in a security architecture, such as a host, web proxy, DNS servers, email server, firewall, directory servers, or application authentication gateways. The type of element blocked is influenced by the access control location. DNS servers may be well-suited to block domain names, for example, but not URLs. A firewall is well-suited for blocking IP addresses but less so for blocking malicious files or passwords. Example uses include a company that might prevent a list of software from running on its network, a school that might prevent access to a list of web sites from its computers, or a business that wants to ensure their computer users are not choosing easily guessed, poor passwords.